WASHINGTON B — WASHINGTON -- The staff of the National Association for the Advancement of Colored People has drafted a report strongly criticizing Judge Clarence Thomas for his views on affirmative action and his lack of commitment to the enforcement of civil rights laws.

Some NAACP board members predicted that the report would be the basis for an announcement by the group today that it would oppose the black appellate judge's nomination to the Supreme Court.

The document, prepared by the NAACP's Washington office, stops short of recommending that the nation's largest civil rights group oppose Thomas' nomination. But in its tone and its analysis of Thomas' speeches and his record as an official in the Reagan and Bush administrations, the document leaves little doubt that its authors believe he should not join the High Court.

The report seems to reflect the mood that prevailed among many of the 64 board members during the group's annual convention in Houston earlier this month.

At that time, according to some members, the board voted overwhelmingly to oppose the nomination, but the majority then acceded to the wishes of the minority that no formal action be taken until an assessment could be done of Thomas' speeches and writings and of his work as head of the Office of Civil Rights in the Education Department and as chairman of the Equal Employment Opportunity Commission.

"There was a clear majority of people who wanted to act at that time," said William Lucy, an official with the American Federation of State, County and Municipal Employees and a member of the board. "But people felt there was some wisdom in getting the full record."

Thomas did receive support yesterday from a group of women, a number of whom hold positions in the Bush administration, who announced the formation of Women for Judge Thomas.

The opposition of the NAACP would be a setback to the administration's effort to avoid a divisive battle like the one in 1987, when President Ronald Reagan nominated Judge Robert H. Bork to the Supreme Court.

Of all the predominantly black civil rights groups, only the NAACP has the resources and political clout to mobilize black voters, especially in the South, to effectively press moderate Democratic senators to vote against the nomination.

The group's decision comes as both the administration and Thomas' detractors are marshaling their forces for the Senate fight over the nomination.